/**
 * @author ZhangHuihua@msn.com
 * ----------------------------------------------------------
 * These functions use the same 'format' strings as the 
 * java.text.SimpleDateFormat class, with minor exceptions.
 * The format string consists of the following abbreviations:
 * 
 * Field        | Full Form          | Short Form
 * -------------+--------------------+-----------------------
 * Year         | yyyy (4 digits)    | yy (2 digits), y (2 or 4 digits)
 * Month        | MMM (name or abbr.)| MM (2 digits), M (1 or 2 digits)
 *              | NNN (abbr.)        |
 * Day of Month | dd (2 digits)      | d (1 or 2 digits)
 * Day of Week  | EE (name)          | E (abbr)
 * Hour (1-12)  | hh (2 digits)      | h (1 or 2 digits)
 * Hour (0-23)  | HH (2 digits)      | H (1 or 2 digits)
 * Hour (0-11)  | KK (2 digits)      | K (1 or 2 digits)
 * Hour (1-24)  | kk (2 digits)      | k (1 or 2 digits)
 * Minute       | mm (2 digits)      | m (1 or 2 digits)
 * Second       | ss (2 digits)      | s (1 or 2 digits)
 * AM/PM        | a                  |
 *
 * NOTE THE DIFFERENCE BETWEEN MM and mm! Month=MM, not mm!
 * Examples:
 *  "MMM d, y" matches: January 01, 2000
 *                      Dec 1, 1900
 *                      Nov 20, 00
 *  "M/d/yy"   matches: 01/20/00
 *                      9/2/00
 *  "MMM dd, yyyy hh:mm:ssa" matches: "January 01, 2000 12:30:45AM"
 * ----------------------------------------------------------
 */
(function(){
var MONTH_NAMES=new Array('January','February','March','April','May','June','July','August','September','October','November','December','Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec');
var DAY_NAMES=new Array('Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday','Sun','Mon','Tue','Wed','Thu','Fri','Sat');
function LZ(x) {return(x<0||x>9?"":"0")+x}

/**
 * formatDate (date_object, format)
 * Returns a date in the output format specified.
 * The format string uses the same abbreviations as in parseDate()
 * @param {Object} date
 * @param {Object} format
 */
function formatDate(date,format) {
    format=format+"";
    var result="";
    var i_format=0;
    var c="";
    var token="";
    var y=date.getYear()+"";
    var M=date.getMonth()+1;
    var d=date.getDate();
    var E=date.getDay();
    var H=date.getHours();
    var m=date.getMinutes();
    var s=date.getSeconds();
    var yyyy,yy,MMM,MM,dd,hh,h,mm,ss,ampm,HH,H,KK,K,kk,k;
    // Convert real date parts into formatted versions
    var value={};
    if (y.length < 4) {y=""+(y-0+1900);}
    value["y"]=""+y;
    value["yyyy"]=y;
    value["yy"]=y.substring(2,4);
    value["M"]=M;
    value["MM"]=LZ(M);
    value["MMM"]=MONTH_NAMES[M-1];
    value["NNN"]=MONTH_NAMES[M+11];
    value["d"]=d;
    value["dd"]=LZ(d);
    value["E"]=DAY_NAMES[E+7];
    value["EE"]=DAY_NAMES[E];
    value["H"]=H;
    value["HH"]=LZ(H);
    if (H==0){value["h"]=12;}
    else if (H>12){value["h"]=H-12;}
    else {value["h"]=H;}
    value["hh"]=LZ(value["h"]);
    if (H>11){value["K"]=H-12;} else {value["K"]=H;}
    value["k"]=H+1;
    value["KK"]=LZ(value["K"]);
    value["kk"]=LZ(value["k"]);
    if (H > 11) { value["a"]="PM"; }
    else { value["a"]="AM"; }
    value["m"]=m;
    value["mm"]=LZ(m);
    value["s"]=s;
    value["ss"]=LZ(s);
    while (i_format < format.length) {
        c=format.charAt(i_format);
        token="";
        while ((format.charAt(i_format)==c) && (i_format < format.length)) {
            token += format.charAt(i_format++);
        }
        if (value[token] != null) { result += value[token]; }
        else { result += token; }
    }
    return result;
}

function _isInteger(val) {
    return (new RegExp(/^\d+$/).test(val));
}
function _getInt(str,i,minlength,maxlength) {
    for (var x=maxlength; x>=minlength; x--) {
        var token=str.substring(i,i+x);
        if (token.length < minlength) { return null; }
        if (_isInteger(token)) { return token; }
    }
    return null;
}

/**
 * parseDate( date_string , format_string )
 * 
 * This function takes a date string and a format string. It matches
 * If the date string matches the format string, it returns the date. 
 * If it does not match, it returns 0.
 * @param {Object} val
 * @param {Object} format
 */
function parseDate(val,format) {
    val=val+"";
    format=format+"";
    var i_val=0;
    var i_format=0;
    var c="";
    var token="";
    var token2="";
    var x,y;
    var now=new Date(1900,0,1);
    var year=now.getYear();
    var month=now.getMonth()+1;
    var date=1;
    var hh=now.getHours();
    var mm=now.getMinutes();
    var ss=now.getSeconds();
    var ampm="";
    
    while (i_format < format.length) {
        // Get next token from format string
        c=format.charAt(i_format);
        token="";
        while ((format.charAt(i_format)==c) && (i_format < format.length)) {
            token += format.charAt(i_format++);
        }
        // Extract contents of value based on format token
        if (token=="yyyy" || token=="yy" || token=="y") {
            if (token=="yyyy") { x=4;y=4; }
            if (token=="yy")   { x=2;y=2; }
            if (token=="y")    { x=2;y=4; }
            year=_getInt(val,i_val,x,y);
            if (year==null) { return 0; }
            i_val += year.length;
            if (year.length==2) {
                if (year > 70) { year=1900+(year-0); }
                else { year=2000+(year-0); }
            }
        } else if (token=="MMM"||token=="NNN"){
            month=0;
            for (var i=0; i<MONTH_NAMES.length; i++) {
                var month_name=MONTH_NAMES[i];
                if (val.substring(i_val,i_val+month_name.length).toLowerCase()==month_name.toLowerCase()) {
                    if (token=="MMM"||(token=="NNN"&&i>11)) {
                        month=i+1;
                        if (month>12) { month -= 12; }
                        i_val += month_name.length;
                        break;
                        }
                    }
                }
            if ((month < 1)||(month>12)){return 0;}
        } else if (token=="EE"||token=="E"){
            for (var i=0; i<DAY_NAMES.length; i++) {
                var day_name=DAY_NAMES[i];
                if (val.substring(i_val,i_val+day_name.length).toLowerCase()==day_name.toLowerCase()) {
                    i_val += day_name.length;
                    break;
                }
            }
        } else if (token=="MM"||token=="M") {
            month=_getInt(val,i_val,token.length,2);
            if(month==null||(month<1)||(month>12)){return 0;}
            i_val+=month.length;
        } else if (token=="dd"||token=="d") {
            date=_getInt(val,i_val,token.length,2);
            if(date==null||(date<1)||(date>31)){return 0;}
            i_val+=date.length;
        } else if (token=="hh"||token=="h") {
            hh=_getInt(val,i_val,token.length,2);
            if(hh==null||(hh<1)||(hh>12)){return 0;}
            i_val+=hh.length;
        } else if (token=="HH"||token=="H") {
            hh=_getInt(val,i_val,token.length,2);
            if(hh==null||(hh<0)||(hh>23)){return 0;}
            i_val+=hh.length;}
        else if (token=="KK"||token=="K") {
            hh=_getInt(val,i_val,token.length,2);
            if(hh==null||(hh<0)||(hh>11)){return 0;}
            i_val+=hh.length;
        } else if (token=="kk"||token=="k") {
            hh=_getInt(val,i_val,token.length,2);
            if(hh==null||(hh<1)||(hh>24)){return 0;}
            i_val+=hh.length;hh--;
        } else if (token=="mm"||token=="m") {
            mm=_getInt(val,i_val,token.length,2);
            if(mm==null||(mm<0)||(mm>59)){return 0;}
            i_val+=mm.length;
        } else if (token=="ss"||token=="s") {
            ss=_getInt(val,i_val,token.length,2);
            if(ss==null||(ss<0)||(ss>59)){return 0;}
            i_val+=ss.length;
        } else if (token=="a") {
            if (val.substring(i_val,i_val+2).toLowerCase()=="am") {ampm="AM";}
            else if (val.substring(i_val,i_val+2).toLowerCase()=="pm") {ampm="PM";}
            else {return 0;}
            i_val+=2;
        } else {
            if (val.substring(i_val,i_val+token.length)!=token) {return 0;}
            else {i_val+=token.length;}
        }
    }
    // If there are any trailing characters left in the value, it doesn't match
    if (i_val != val.length) { return 0; }
    // Is date valid for month?
    if (month==2) {
        // Check for leap year
        if ( ( (year%4==0)&&(year%100 != 0) ) || (year%400==0) ) { // leap year
            if (date > 29){ return 0; }
        } else { if (date > 28) { return 0; } }
    }
    if ((month==4)||(month==6)||(month==9)||(month==11)) {
        if (date > 30) { return 0; }
    }
    // Correct hours value
    if (hh<12 && ampm=="PM") { hh=hh-0+12; }
    else if (hh>11 && ampm=="AM") { hh-=12; }
    return new Date(year,month-1,date,hh,mm,ss);
}

Date.prototype.formatDate = function(dateFmt) {
    return formatDate(this, dateFmt);
};
String.prototype.parseDate = function(dateFmt) {
    if (this.length < dateFmt.length) {
        dateFmt = dateFmt.slice(0,this.length);
    }
    return parseDate(this, dateFmt);
};

/**
 * replaceTmEval("{1+2}-{2-1}")
 */
function replaceTmEval(data){
    return data.replace(RegExp("({[A-Za-z0-9_+-]*})","g"), function($1){
        return eval('(' + $1.replace(/[{}]+/g, "") + ')');
    });
}
/**
 * dateFmt:%y-%M-%d
 * %y-%M-{%d+1}
 * ex: new Date().formatDateTm('%y-%M-{%d-1}')
 *     new Date().formatDateTm('2012-1')
 */
Date.prototype.formatDateTm = function(dateFmt) {
    var y = this.getFullYear();
    var m = this.getMonth()+1;
    var d = this.getDate();

    var sDate = dateFmt.replaceAll("%y",y).replaceAll("%M",m).replaceAll("%d",d);
    sDate = replaceTmEval(sDate);
    
    var _y=1900, _m=0, _d=1;
    var aDate = sDate.split('-');
    
    if (aDate.length > 0) _y = aDate[0];
    if (aDate.length > 1) _m = aDate[1]-1;
    if (aDate.length > 2) _d = aDate[2];
    
    return new Date(_y,_m,_d).formatDate('yyyy-MM-dd');
};

})();

